1. Field of the Invention
This invention relates to data acquisition multiplexing systems and, more particularly, relates to such systems which are adaptively reconfigurable.
2. Background Art
Data multiplexing system requirements for parameter measurements at a first location, transmission to and display at a second remote location typically do not change rapidly over time, a common example of which is illustrated in conventional plant process controller multiplexing systems. Thus, for many such applications, fixed hardware/software data multiplexing configurations have been adequate. When relatively infrequent instances arose necessitating post-installation system hardware reconfiguration, lead times were typically sufficient to effect the changes with minimal down time and expense. Thus, such systems were relatively flexible, provided that this lead time was available.
However, situations have arisen in the process control and data multiplexing arts wherein system parameter measurement changes often were extensive and/or desirably to be effected over relatively short periods of time. Notable examples of this occur in (1) space data system applications wherein system requirements may change between flights scheduled relatively short time periods apart; and, (2) production run plant process control applications wherein the production line and thus the production parameter measurement needs change with introduction of a new product or change in process controls to improve product quality.
Prior art systems required costly and time consuming data multiplexing hardware changeouts or modifications to meet the changing system demands. This, in turn, gave rise to numerous problems associated with the need for additional redesign, installation, and testing to effect the system changes. Due to these aforementioned problems, it was not uncommon to find that in many applications important and highly desired system changes for effecting parameter measurements were either never implemented or delayed, thus resulting in substandard system performance during the interim until the changes could be effected.
For the aforementioned reasons, technology developed which sought to ease the reconfigurability of data multiplexing systems. However, several drawbacks were associated with these attempts. One approach simply sought to facilitate the task of hardware changeouts, however this was ineffectual due to the sheer variety of apparatus associated with such data systems. Moreover, a fundamental problem still remained in the inability to reconfigure the data multiplexing system in real time during parameter measurement. But one example illustrating the need for this capability in data multiplexing systems occurs wherein measured data exceeds full scale during a production run, space flight, or the like. Valuable data is lost because the parameter measuring system may not be reconfigured or adjusted during the derivation of these measurements (due to the attendant need for hardware changes irrespective of how efficiently they may be implemented).
Yet, another approach sought to make changes in the remote measurement generating terminal by way of a central process or system control computer. However, these systems typically required a relatively complex central computer and associated highly trained operator effecting such reconfiguration as well as relatively complex software being resident at the central process control computer. Moreover, such systems in the prior art typically effected a relatively simple change in a measurement parameter as, for example, in varying at a remote location a single gain level of an instrumentation amplifier or the like.
From the foregoing, it will be readily apparent that it was highly desirable to provide a flexible data acquisition and multiplexing system which might be easily and inexpensively reconfigured on-line without the need for highly trained personnel. Moreover, such a system would further be desired which could be reconfigured in real time during derivation and transmission of measurements to meet changing parameter measurement conditions.
Still further, such a system would be desired which could facilitate reconfiguration by the relatively unskilled operator with highly simplified reconfiguration equipment, and wherein the same data acquisition/multiplexing hardware could remain in situ thereby avoiding the necessity of hardware changeouts or modifications.
Accordingly, a novel data acquisition and multiplexing system is provided having one or more remote terminals which store internally their own configuration parameter status for remote display and which contain software to transmit CRT menu/data page format instructions along with present parameter settings and real time data values to a simple monitor/keyboard terminal for operator information and use.